Animal semen preparations of increased fertility

ABSTRACT

The fertility of animal semen preparations is increased by adding Beta -glucuronidase thereto.

United-States Patent [1 1 [111 3,718,740

Hafs et al. [451 Feb. 27, 1973 [54] ANIMAL SEMEN PREPARATIONS 0F INCREASED FERTILITY [56] References Cited [75] Inventors: Harold D. Hafs; Louis J. Boyd, both OTHER PUBLICATIONS of okemos Mlch' Doepfmer et al. Chem. Abst. Vol. 60 (9164) page [7 3] Assignee: Research Corporation, New York, 5936d N.Y. Primary ExaminerSam Rosen [22] led: March 1971 Attorney-Stowe & Stowell [21] App]. No.: 125,861

[57] ABSTRACT The fertility of animal semen preparations is increased [52] US. Cl. ..424/105, l95/1.8, 424/94 51 Int. Cl. ..A6lk 17/00 by addmg B glucummdase [58] Field of Search ..424/105, 94; 195/ 1.8 5 Claims, No Drawings ANIMAL SEMEN PREPARATIONS OF INCREASED FERTILITY This invention relates to a method for increasing the fertility of animal semen preparations intended for use in the breeding ofdomestic animals.

In practicing artificial insemination, it is conventional practiceto make semen preparations by diluting freshly ejaculated semen with a diluent and store the extended preparation under refrigeration or in the frozen condition. Egg yolk dispersed in a suitably buffered aqueous system (generally citrate at about pH 6.8) containing small amounts of minerals, nutrients and antibiotics is commonly used as the diluents or extender.

We have discovered that the motility and fertility of the spermatozoa in animal semen preparations are increased when B-glucuronidase is added thereto. fl-glucuronidase is an enzyme which catalyzes the hydrolytic cleavage of the glucoside bond of glucuronides. While the exact mechanism whereby B-glucuronidase increases semen fertility is not known, it appears related to its activity as a carbohydrase.

More specifically, the present invention is a method for increasing the fertility of animal semen preparations which comprises adding an effective amount of B-glucuronidase thereto. The invention also contemplates the semen preparations of increased fertility thereby produced.

The present invention is illustrated by special reference to bull semen preparations because of the great economic importance of cattle breeding. However, the method of the present invention is applicable to increasing the fertility of animal semen preparations generally.

In practicing the present invention, freshly ejaculated neat semen is diluted with from about to 200 parts of egg yolk-citrate or other suitable diluent solution. The extent of dilution depends primarily on the concentration of spermatozoa in the semen being treated. While 10 million spermatozoa per milliliter of preparation are generally thought sufficient to insure conception, the better practice is to formulate the preparation to contain at least million spermatozoa per milliliter.

We have discovered that the addition of as little as 10 Fishman units of B-glucuronidase per milliliter of semen preparation results in a perceptible increase in motility and fertility of the spermatozoa in the preparation as compared to an untreated control. The increase in fertility obtained is approximately linear with the amount of B-glucuronidase added at lower concentrations but levels off at higher concentrations (300 Fishman units per milliliter maximum tested) depending on the length of storage of the semen preparation. The longer the period of storage prior to utilization, the greater the benefit obtained by adding B-glucuronidase at higher concentrations.

Our invention is further illustrated by means of the following non-limiting examples;

Freshly ejaculated bull semen was treated with 0, and 300 Fishman units of mollusc B-glucuronidase per milliliter of 20 percent egg yolk-2.32 percent sodium citrate dihydrate diluent containing 500 ug of streptomycin and 500 units of penicillin. (Stock enzyme preparation was diluted by solution in 0.85 percent saline and added to the semen diluent preparation Fishman units B-glucuronidase motile spermatozoa after storage 1 day 7 days 0 (control) 48 17 3O 54 21 300 53 35 In another series of experiments, one milliliter of 0.85 percent saline containing 6,000 Fishman units of mollusc B-glucuronidase was added to each 99 milliliters of 20 percent egg yolk-2.32 percent sodium citrate dihydrate semen diluent; 1 milliliter of saline without enzyme was added to each 99 milliliters of control diluent. Glycerolation 2 to 4 hours later with an equal volume of the same diluent containing 14 percent glycerol but no B-glucuronidase brought the concentration of enzyme to 30 units/ml in the enzyme treated preparations. Seven semen preparations treated with B- glucuronidase and 15 control semen preparations, each preparation containing about 30 X 10 spermatozoa/ml, were equilibrated for about 20 hours and then frozen. The to -day nonreturn fertility rate in 1,292 cows inseminated with control semen preparation was 67.2 percent. This was significantly (P 0.05) less than the 74.1 percent nonreturn rate in 279 cows inseminated with semen preparation containing 30 units of B-glucuronidase per milliliter.

In another series of experiments, all of the semen samples obtained from 14 bulls in routine service were treated alike on any given semen collection day. Enzyme treatment was assigned at random to three semen collection days. In each enzyme treatment series, 1 milliliter of saline (control) or saline containing enzyme was added to the semen diluent as in the previous series. Ampules of the frozen semen preparations were stored at l C. for 2 weeks to 6 months before thawing in water at 5C. preparatory to insemination. Details of the insemination and the results obtained are summarized below:

Fishman No.of No.0f First fertility units B-glucuroni Bulls Ejacula Services 60- to 90-day dasc nonreturn 0 (control) 14 26 3,401 72.0 l0 l2 18 1,961 72.3 30 12 22 1,912 73.2 l5() 9 16 1,734

l. A method for increasing the fertility of animal semen preparations which comprises adding an effective amount of fi-glucuronidase thereto.

2. A method according to claim 1 wherein said amount of B-glucuronidase is at least 10 Fishman units per milliliter of preparation.

3. A method for increasing the fertility of a bull semen preparation which comprises adding B glucuronidase thereto in an amount of at least Fishman lo 

2. A method according to claim 1 wherein said amount of Beta -glucuronidase is at least 10 Fishman units per milliliter of preparation.
 3. A method for increasing the fertility of a bull semen preparation which comprises adding Beta glucuronidase thereto in an amount of at least 10 Fishman units per milliliter of preparation.
 4. A animal semen preparation having an increased fertility comprising an animal semen and an effective amount of Beta -glucuronidase added theretO.
 5. A bull semen preparation comprising bull semen extended with egg yolk citrate and at least 10 Fishman units per milliliter of preparation of added Beta -glucuronidase. 